back to article PlayStation-processor-powered plutonium probe prepares Pluto pics

After a trip of nearly three billion miles, NASA’s New Horizons spacecraft, our first probe to Pluto, will on Wednesday start sending back up-close pictures of the dwarf planet. The craft was sent into our Solar System's obsidian void on January 19, 2006 – back when Pluto was still considered a planet in its own right. Later …

  1. Robert Helpmann?? Silver badge
    Childcatcher

    Routers... in Space!

    That also cuts down on bandwidth, and at this far out, the best data speed possible is about 700 bits per second.

    It has struck me that the issue of phoning home almost always is mentioned in articles of this nature. I know it is not as interesting to talk about as beautiful pics sent from far-off worlds, but if we are going to explore, colonize, or make use of the resources elsewhere in the solar system, shouldn't we be at least thinking about putting up some infrastructure? Yes, communication satellites would be expensive with no immediate return, but they would, I hope, have some long term benefits. I found a number of proposed solutions online, but nothing actually being planned. Anybody else?

    1. Voland's right hand Silver badge

      Re: Routers... in Space!

      Why bother? Excuse me for being blunt, but we are not putting anything out into that region anytime soon. Pu 238 is not manufactured any more so even if we get our s**t together to launch something there is nothing to fuel it with. It will take years to replenish the supply to a reasonable level so that outer solar system launches can start once more. Am 241 generators are still in their infancy, it will take a decade or so to get to the point where they can be incorporated into designs.

      So from that perspective the overall situation with missions past the Saturn orbit looks pretty grim.

      Otherwise, from the perspective of "Earth to Dave" communication the gain and signal to noise ratios of the dishes and dish systems harnessed for this purpose on Earth are phenomenal. There is nothing you can gain on top of that using a space relay.

      This leaves only one use case for an interplanetary relay - the communicating probe being behind the Sun and us in a desperate need to have semi-realtime link to it. Frankly, we are not exploring the solar system at a rate where this is necessary. Once it becomes necessary we are perfectly capable of slotting something into Earth-Sun L4 or L5 which should do the job. Several probes have passed reasonably close to that already (STEREO-A/B, Spitzer, etc).

      1. boltar Silver badge

        Re: Routers... in Space!

        "So from that perspective the overall situation with missions past the Saturn orbit looks pretty grim."

        Even though I'm a space buff too, given the choice of space missions or little to no plutonium on earth I'd take the latter any day.

        As an aside, I presume uranium is simply to heavy and/or not radioactive enough to fuel a probe?

        1. Destroy All Monsters Silver badge

          Re: Routers... in Space!

          Even though I'm a space buff too, given the choice of space missions or little to no plutonium on earth I'd take the latter any day.

          WHY? I see no problem with Pu on Earth except the one in nukes and dumped into the environment, and the annoying filling of pants that antinuxers perform whenever the subject is even mentioned. Yes, it's a nasty element in daily bodily processes. Don't ingest it.

          That being said, for probes you need the special kind of Pu that alpha-decays, generating lots of heat. The temperature difference thus created powers the RTGs on space probes. This Pu can only be made in special reactors from Neptunium.

          The standard Pu is not particulary decay-happy and just sits there with low alpha activity, mainly waiting for neutron showers..

          1. Alan Brown Silver badge

            Re: Routers... in Space!

            "That being said, for probes you need the special kind of Pu"

            Which is unsuitable for bomb making (any level of Pu238 renders plutonium useless for bombs), one of the reasons it's hard to obtain (current uranium reactor designs were optimised for weapons production and adapted to civil operation as an afterthought).

            LFTR designs produce masses of Pu238, which can be left in-situ to burn down, or extracted for RTGs, along with substantial quantities of helium (they'd eliminate fears of a helium shortage) and other noble gasses (although these would need to sit for a few years in order to get rid of remaining "hot" radionucleides - they're ready about a decade after extraction)

      2. cray74

        Re: Routers... in Space!

        "Pu 238 is not manufactured any more"

        Oakridge resumed production in 2013 with its High Flux Isotope Reactor, targeting 1.5kg/year of Pu238 production.

      3. Acme Fixer

        Re: Routers... in Space!

        I found it amusing that the probe to Pluto was powered by PLUTOnium.

    2. Annihilator
      Boffin

      Re: Routers... in Space!

      Three reaons against that immediately spring to mind:

      1) Where are you putting these relays? They would either be in orbit around a planet, or in a sun-orbit similar to a planet orbits. Orbital mechanics means that they wouldn't be in alignment very often (so right now, Jupter is pretty close to Earth, but Pluto is further away from Jupiter than it is from Earth due to it being on the opposite side of the Sun, while Jupiter is currently on the same side of the sun as us. We're currently closer to Mercury than we are to Mars)

      2) Power, as someone else has already mentioned - how long would these things last?

      3) Interplanetary comms relies on a massive dish/array at one end (for ease of logistics, we tend to keep that one on earth), and a small dish at the other - massive dish to be able to hear the feeble signal coming back from the small dish in space, and powerful enough to blast a mighty signal out that will stand a chance of being heard that far away. A relay comms satelite in Jupiter wouldn't be powerful enough or have a big enough dish to talk to a probe near Pluto, even if it were halfway between Earth and Pluto.

      1. hammarbtyp Silver badge

        Re: Routers... in Space!

        All good and valid points.

        However I wonder.

        1. If you positioned one at each of the Jupiter Lagrange points, would that give you enough coverage?

        2. Enough nuclear power would keep them in operation for some time

        3. Without gravity, surely it is easier to deploy large dishes since they do not need bracing to keep them from collapsing.

        Also while it is not communicating with spacecraft it could be doing other things like radio astrononmy far away from noisy radio spectrum.

        Just some ideas of the top of my head(or another part of my anatomy)

        1. Annihilator

          Re: Routers... in Space!

          You'd need a lot of station-keeping to keep it at the Lagrange points (I assume you mean the Lagrange points of the Sun-Jupiter system), and you'd probably only choose 4 of them. But now you're talking about 4. And I'm not sure that we have any realistic nuclear generated propulsion designs that could cater for that.

          "Size of dish" isn't the only consideration, it needs to broadcast in the 100's of kW range. For comparison, Curiosity's generates significantly less than a kW.

          1. hammarbtyp Silver badge

            Re: Routers... in Space!

            Excuse my ignorance but...

            Is it any different to keeping a large telescope like the James Webb in a lagrange point, which is the current plan? A relay would be cheaper and as long as you could get 20 years out of it, cost effective to replace

            I am not sure why it would need 100's of KW. The fact the signal can be buffered and re-sent means you can improve data rates and s/N with not a large power increase.

            Of course, the other option is to increase the signal by looking at things like masers to send the data, if the tracking issues can be solved

            1. Annihilator

              Re: Routers... in Space!

              "I am not sure why it would need 100's of KW. The fact the signal can be buffered and re-sent means you can improve data rates and s/N with not a large power increase."

              The inverse square law. The power of the signal diminishes exponentially over distance. So at one end of the communication you have to be shouting extra loud (lots of power) or listening extra hard at the other end. Fine between the relay and here, but not between the relay and the probe at Pluto. Two small and/or low powered dishes cannot talk over interplanetary distances.

              As for the James Watt, getting to the sun/earth L2 point is a lot easier than getting to sun/jupiter L2 point.

        2. Alan Brown Silver badge

          Re: Routers... in Space!

          "3. Without gravity, surely it is easier to deploy large dishes since they do not need bracing to keep them from collapsing."

          Theoretically, you could build a dish as large as you want.

          Practically, you need to be able to pack it small enough to fit inside the cargo area on the hose of a launcher AND be sure it'll unfold once it's out there (they get the hell shaken out of them on the way up). There are no dextrous robots or people out there to kick the thing if it jams.

          More than one mission has been crippled by a dish which didn't deploy.

      2. Ken Hagan Gold badge

        Re: Routers... in Space!

        " Interplanetary comms relies on a massive dish/array at one end (for ease of logistics, we tend to keep that one on earth), and a small dish at the other "

        To elaborate, the distance to Neptune (Pluto's orbit is irregular) is about 30AU. A dish near Jupiter (5AU) would spend roughly half of its time on the wrong side of its orbit and would actually be further away than Earth, so let's assume you have several. Even at its closest point, it is still 25AU from Neptune and to be worth doing, the dishes around Jupiter would need to be at least 5/6 of the diameter of the one on Earth. (They need to subtend the same solid angle.) Then they have to re-transmit the message back, but that's a much easier problem because the transmitter can be only 1/36 of the power of the one near Neptune and still deliver the same signal strength to Earth.

        Move the intermediate to Saturn, at 10AU, and you need only 2/3 of the diameter of a dish on Earth, but you've got to get all the dishes out as far as Saturn *and* the retransmission needs to be four times more powerful.

        It would appear that the economics are overwhelmingly weighted in favour of a single hop to a bloody enormous dish on Earth, where construction costs are essentially free (by comparison), power consumption (for transmission back to the craft) is no object, and there's always the options of technological upgrades and repairs whilst the mission is in progress.

  2. Huntsman

    Ashes?

    Am I missing something here, but how could Tombaugh's ashes have been placed on board if he didn't pass until a year after launch?

    1. LDS Silver badge

      Re: Ashes?

      Tombaugh died in 1997. The probe was launched in 2006.

      1. Huntsman
        Unhappy

        Re: Ashes?

        Whoops! That will explain it, blame the man flu and chest infection on my momentary lapse of reason...

  3. eJ2095

    Wonder

    As its Plutonium powered how they stopped it going back in time once it hit 88mph...

    1. Lord Raa

      Re: Wonder

      It only produces 240W, not the 1.21GW required to power a flux capacitor.

      1. Kane Silver badge
        Thumb Up

        Re: Wonder

        But, once it gets there, we will see some serious shit.

    2. Annihilator

      Re: Wonder

      The journey was only meant to take 6 months, the on-board time-machine was set to the same as the one in Back To The Future 2 which meant when it activated it took it to 2015...

  4. adnim Silver badge
    Joke

    Clyde W. Tombaugh, discoverer of Pluto

    The Plutonians may have something to say about that.

    Never finding evidence of life on Pluto indicates that any civilisation won't be technologically advanced and therefore uncivilised or savage. So..... Is there any paste and pinchbeck jewellery or bits of coloured glass on board with which to buy the planet from the locals? We could provide some funds for literacy and vocational studies and relocate them to a reservation on Sedna, Perhaps build some bars and gambling houses for recreational purposes.

    1. Destroy All Monsters Silver badge

      Re: Clyde W. Tombaugh, discoverer of Pluto

      The Plutonians may have something to say about that.

      All of them are dwarfs and will not be taken seriously.

  5. cmannett85

    "...at this far out, the best data speed possible is about 700 bits per second."

    But I thought all comms were done through subspace?

    1. Mike Bell

      Hands up, anybody, who remembers US Robotics modems that weren't much faster than that.

      1. paulc

        Old Skool BBS

        who remembers BBS directories with comments beside images "Worth the cost of the download"?

      2. EddieD

        <raises hand>

        My flatmate in the 80s was a computer dude, who set me on the downward path to IT... Our first modem (USR) could be configured as either 1200/75 or 300 baud duplex...

        We then got (from my dad, ex a drug company) a 1200 duplex modem and were the envy of...well, no-one, until I then discovered USENET, and my soul was forever lost...

        700baud over 30+ AU - that's impressive, and when I see the images and all the other discoveries that the boffins get from this trickle of data - well, impressed is no longer enough, and I have to give into awe (thanks Mr Adams).

        We need more of NASA and less of NSA...

  6. JDX Gold badge
    Mushroom

    Light, camera, wait - what about the light?

    40X further from the Sun than Earth is, there can't be a whole lot of light to take pictures. Does that mean pictures will inevitably be low-quality or does it carry a massive flash-bulb?

    1. DropBear Silver badge
      Joke

      Re: Light, camera, wait - what about the light?

      Well... what did you think the Plutonium was for?!?

    2. Little Mouse

      Re: Light, camera, wait - what about the light?

      Just from a purely photography perspective it's going to be really interesting to see the results.

      Not enough light. Subject and camera both moving at silly speeds. Precious little chance to chimp the results whilst rattling off the shots. And presumably the sunny 16 rule is all shot to hell as well.

      Does anyone know the specs of the camera equipment they're using?. It's a general truism that it's the photographer not the lens that counts, but under these conditions some decent kit couldn't hurt.

      On the plus side I assume they have some pretty smart people working on this - plus a shed load of post-processing power back home.

      1. JeffyPoooh Silver badge
        Pint

        Re: Light, camera, wait - what about the light?

        LM: "...general truism that it's the photographer not the lens that counts..."

        'Location' should be explicitly mentioned in such lists.

        1. Little Mouse
          Trollface

          Re: Light, camera, wait - what about the light?

          You may have a point. That would go some way towards explaining why all my photos of Aberdeen look so grim.

    3. Acme Fixer

      Re: Light, camera, wait - what about the light?

      3e9 / 93e6 equals 32.something. The inverse square is 1/1040 the light of the earth's, but Pluto has no atmosphere to block out all the UV and IR, etc. Knowing how bright old Sol is here, it doesn't seem like Pluto is dimly lit. How many f stops is 1/1000?

  7. BernardL

    "Interred" surely?

    Or was "Interned" a pun rather than a misprint, since there's no actual terra to be interred in?

  8. Wombling_Free

    They don't make them like they used to.

    And sadly, given our current attitudes, they probably won't ever again.

  9. Doctor Syntax Silver badge

    "As New Horizons screams"

    In space nobody can hear...

  10. Elmer Phud

    Speedy Snaps

    "NASA estimates it will take at least nine months to download all the data and imagery collected from Pluto."

    This sort of info should be repeated until the 'Where's the pictures?' moans have stopped -- the moans that start as soon as we get contact with a craft after years of travel.

    ( I am surprised that I've yet to see a comment about comparisons of mobile companies and speeds)

  11. batfastad
    Coat

    Line profile?

    700bps at a distance from the exchange of 3bn miles is impressive compared to our 4Mbps at only 3 miles. Mind you, our latency is better than 4hrs.

    1. I ain't Spartacus Gold badge
      Happy

      Re: Line profile?

      New Horizons is still waiting for its refund, given that there's no longer an offline only version of the new Elite. It's having serious problems with lag whenever it tries a bit of PVP action. On the plus side though, it's already got a docking computer at JPL, so doesn't need to buy one.

  12. Anonymous Coward
    Anonymous Coward

    Don't worry..

    RIZON will return in about 300 years looking for a carrier signal...

  13. DougS Silver badge
    Terminator

    Good thing it doesn't have an AI

    Otherwise when it was awakened for the approach to Pluto it might get depressed or pissed off when it found out about Pluto's demotion and not do its job!

    1. Martin Budden Bronze badge
      Unhappy

      Re: Good thing it doesn't have an AI

      It can't get depressed: it only has a 32-bit 12MHz Mongoose V processor, not a brain the size of a (recently-demoted dwarf) planet.

      Icon: Marvin, innit.

  14. Laurel Kornfeld

    Pluto IS still considered a planet in its own right by many planetary scientists and astronomers. It is unfortunate that you report one position in an ongoing debate as fact when this is not the case. Only four percent of the IAU voted on the controversial demotion, and most were not planetary scientists. Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Stern, Principal Investigator of the New Horizons mission. Ironically, Stern is the person who first coined the term "dwarf planet," but he intended it to designate a third class of planets in addition to terrestrials and jovians, not to designate non-planets.

    It turns out that other than there are no known objects larger than Pluto in the region beyond Neptune. Eris was initially thought to be larger than Pluto, but in November 2010, a team of astronomers led by Dr. Bruno Sicardy obtained a more accurate measurement of Eris when it occulted a star and found it to be marginally smaller than Pluto.

  15. MarkTheMorose
    Alien

    V'ger must join with the Creator.

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